1. Evidence of extreme domain wall speeds under ultrafast optical excitation
- Author
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Jangid, Rahul, Hagström, Nanna Zhou, Madhavi, Meera, Rockwell, Kyle, Shaw, Justin M., Brock, Jeffrey A., Pancaldi, Matteo, De Angelis, Dario, Capotondi, Flavio, Pedersoli, Emanuele, Nembach, Hans T., Keller, Mark W., Bonetti, Stefano, Fullerton, Eric E., Iacocca, Ezio, Kukreja, Roopali, and Silva, Thomas J.
- Subjects
Condensed Matter - Mesoscale and Nanoscale Physics ,Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ,FOS: Physical sciences - Abstract
Time-resolved ultrafast EUV magnetic scattering was used to test a recent prediction of >10 km/s domain wall speeds by optically exciting a magnetic sample with a nanoscale labyrinthine domain pattern. Ultrafast distortion of the diffraction pattern was observed at markedly different timescales compared to the magnetization quenching. The diffraction pattern distortion shows a threshold-dependence with laser fluence, not seen for magnetization quenching, consistent with a picture of domain wall motion with pinning sites. Supported by simulations, we show that a speed of $\approx$ 66 km/s for highly curved domain walls can explain the experimental data. While our data agree with the prediction of extreme, non-equilibrium wall speeds locally, it differs from the details of the theory, suggesting that additional mechanisms are required to fully understand these effects., 5 pages, 4 figures; Supplemental Material: 9 pages, 9 figures
- Published
- 2023